In carrying out certain surgical procedures, it is often necessary to form holes into or through bones. In some situations it may be necessary to form multiple holes having different diameters. It may also be necessary to form a hole in a bone on the first pass of a surgical drill of one diameter, and then to widen that hole (along either part of or all of its length) on a successive pass of a second, larger diameter drill.
To accomplish drilling into bone, one method that has been employed involves first placing a thin guidewire into a bone. Such a guidewire is frequently made of stainless steel. It is typically placed into the bone by tapping on the proximal end of the guidewire or by drilling. After the guidewire is thus installed, it is used to direct one or more drills down its length to effect a drilling operation. For example, the diameter of a tunnel that is formed into the bone using a first drill passed down a guidewire may be sequentially increased (along either part of or all of its length) by employing drills of increasingly larger size and passing them successively down the guidewire into drilling engagement with the bone.
Unfortunately, it can be time-consuming and inconvenient to successively chuck and remove multiple drill bits from a surgical drill during the course of a surgical procedure.
Accordingly, one object of the present invention is to provide a modular drill arrangement in which different drill bits may be readily interchanged on a rigid drill shaft in order to form different sized holes in bone.
Another object of the present invention is to provide a modular drill implement wherein a drill shaft need be chucked only once in a surgical drill in order to complete a surgical procedure which requires making different sized holes in bone.
A further object of the present invention is to provide a method of constructing tunnels in bone wherein a modular drill having a drill bit and a rigid drill shaft is employed in connection with a guidewire, and the interconnection of the drill bit and the rigid drill shaft is secured against displacement by the mounting of the modular drill on the guidewire.
Yet another object of the present invention is to provide a modular drill for use with a guidewire for drilling holes into bone wherein alignment of the drill bit is assured when drilling into bone even though the drill bit may be replaced with another drill bit during the surgical procedure.
A still further object of the present invention is to provide a surgical drilling implement which employs a drill bit and drill shaft, and wherein the interconnection between the drill bit and shaft is such as to readily permit interchanging drill bits, and wherein such drill bits are securely locked relative to the shaft.
Another object of the present invention is to provide a drill bit which, when drilled through bone and upon entering a joint capsule, will not damage adjacent soft tissue structures.
Yet another object of the present invention is to provide means for retrieving a drill bit which becomes disengaged from its associated drill shaft during use.
Still another object of the present invention is to provide improved means for mounting a drill bit to a drill shaft.
And another object of the present invention is to provide a modular drill which will avoid migrating off its drilling axis as it exits the far side of a bone even when that drilling axis extends at an acute angle to the rear surface of the bone.
Yet another object is to provide improved means for forming a bone tunnel through a bone, and thereafter passing a length of suture through that bone tunnel.